Thermal management is an important element of electronic device design. Both the performance reliability and life expectancy of electronic devices are inversely related to operating temperatures of components within the devices. For example, the relationship between reliability and the operating temperature of a typical silicon semi-conductor component shows that a reduction in the temperature of the electronic component corresponds to an exponential increase in the reliability and life expectancy of that component. Therefore, long life and reliable performance of an electronic device may be achieved by effectively controlling operating temperature within the limits set by component design engineers.
Heat sinks enhance heat dissipation from a hot surface, e.g., a heat generating electronic component, to a cooler ambient, e.g., room temperature air. In most cases involving electronic components, air is the coolant. Often, heat transfer across an interface between a component surface and the coolant air is not efficient within a system, and the interface represents a barrier for heat dissipation. A heat sink lessens the effect of the barrier by increasing the surface of the heat generating component that is in direct contact with the coolant. That allows more heat to be dissipated and lowers the electronic component operating temperature.
Prior art heat dissipation solutions often rely on a heat sink used in combination with a fan to provide air flow across the heat sink for thermal convection. If the electronic component is located within a housing, ventilation holes are provided through the housing to allow outside air to flow through the housing. However, ventilation holes allow dust and moisture to enter the housing from the outside and can coat electronic components within the housing, reducing the efficiency of heat transfer between the air and the electronic component and/or the heat sink. A ventilation fan accelerates that coating process.
Further, some electronic devices include audio components in or on the housing. For example, telephones including a hands-free option have a microphone mounted in the telephone base housing, apart from the microphone in the mouthpiece of the telephone hand set. Noise from a ventilation fan in the telephone base housing degrades the quality of the voice sounds acquired by the microphone.
Therefore, it is desired to enable heat dissipation from an electronic component in an enclosed housing that overcomes the problems of the prior art.